Egypt's Muslim Brotherhood on Friday criticised US Secretary of State John Kerry for saying the Egyptian military had been "restoring democracy" when it toppled Islamist president Mohamed Morsi.

In the strongest words of US support yet for the new leadership, Kerry said the Egyptian army had been "restoring democracy" when it toppled Morsi.

"The military was asked to intervene by millions and millions of people, all of whom were afraid of a descent into chaos, into violence," he told Pakistan's GEO TV on Thursday. "And the military did not take over, to the best of our judgment so – so far."

The comments were attacked by Mohamed Ali Bishr, a senior brotherhood leader and a minister in Morsi's former government. "We totally reject these statements and we are very disappointed in them," he said.

"The United States is a country that speaks of democracy and human rights and they say something like that. I hope that they rethink their position and correct it," he told Reuters.

Morsi, a Muslim Brotherhood official who became Egypt's first freely-elected leader in June 2012, was ousted on July 3 and replaced by an army-backed government.

The United States has avoided calling his removal a coup.

Bishr said the US position disregarded the will of the Egyptian people.

The United States has avoided calling Morsi's overthrow a "coup" – a move that would have triggered a cut-off in the $1.3bn of US aid the Egyptian military receives each year.

Kerry, however, has called on Egypt to respect the right of peaceful protest, including pro-Morsi rallies.

Supporters of Morsi prepared for confrontation on Friday. Thousands were gathered in two Muslim Brotherhood camps in Cairo, defying warnings from the new army-backed government to abandon their protest or face action from security forces.

At the main Rabaa al-Adawiya camp on Friday morning, young men wearing crash helmets and brandishing sticks mounted a first line of defence behind barricades of sandbags and bricks.

Political sources said there had been intense debate within the cabinet on the wisdom of the security forces taking action.

Almost 300 people have died in political violence since Morsi was overthrown on July 3, including 80 of his supporters shot dead by security forces in a single incident last Saturday.

Morsi, an Islamist who became Egypt's first freely-elected president in June 2011, had faced weeks of street demonstrations against his rule. Many Egyptians were frustrated by his failure to get to grips with social and economic problems and feared he was leading the country towards stricter Islamist control.